I don't think i've ever actually done HIIT, but I think we did something similar to this when I ran CC and Track. It was basically interval days, we would have a fast interval day and a slow interval day. The slow day we would do like 8-12 400 meter sprints, with 3 minute jogs inbetween, or jog until your heartrate is below 120 bpm if it is under 3 mins of rest, then go again. Times vary based on your mile time.
Fast days, we would do 6 400's, 4 200's and 6 100's, all out, and then rest like 2 mins in between. Those days sucked, came close to blacking out on more than one occasion.
After you build up some cardio, those two workouts are great for boosting it further, it's a good way to really build up your cardio.
You're not drunk if you can lie on the floor without holding on
(n.): Something that can be looked down on and approved of at the same time.